A portion of the Spring Lake aquatic plant survey map showing numbered GPS waypoints. Map provided by Progressive AE.
When and where treatments are conducted is determined by the weather and where nuisance plants are found when biologists from Progressive AE conduct their surveys. Treatments of the lake are typically conducted before Memorial Day, before the 4th of July, and before the Coast Guard Festival.
Why are there still plants in the lake following treatments?
Not all plants are treated. The goal of the program is to strike a balance by controlling invasive plant species and maintaining beneficial species. We do not want to remove all the plants in the lake. This would be bad for the fishery and cause a host of other problems, such as massive algae blooms.
What plants are targeted for control?
The Spring Lake plant control program focuses primarily on invasive, exotic species. An exotic species is one that is found outside of its natural range. Outside their natural range, exotic plants have no natural competitors or predators to help keep them in check. They can quickly outcompete native plants and gain dominance in the lake. Eurasian milfoil is the primary exotic species targeted for control in Spring Lake.
Are herbicide treatments safe?
The aquatic herbicides that are permitted by the Department of Environmental Quality (DEQ) are registered by the United States Environmental Protection Agency and the Michigan Department of Agriculture and Rural Development. They also undergo toxicological review by the DEQ. In Michigan, aquatic herbicide use requires a DEQ permit. The permit lists herbicides approved for use in the lake, respective dose rates, and shows specific areas in the lake where treatments are allowed. If herbicides are applied according to label instructions and permit requirements, they should pose no danger to public health and the environment.
Why didn’t my property get treated?
Treatments occur where the targeted invasive plants are found during the lake surveys. Not every property gets treated every time; your property may have plants, but if it doesn’t contain the targeted invasive plants, it’s not treated.
How will I know about use restrictions?
All lake residents will receive a written notice regarding pending treatments. The written notice will list all herbicides that may be used and use restrictions. At the time of treatment, state regulations require that areas within 100 feet of treatment areas be posted with a sign that lists specific herbicides applied and the associated use restrictions. If there is no sign posted along your property, it means your area was not treated and there are no use restrictions.
When is it safe to swim after a treatment?
All herbicides have a 24-hour swimming restriction that will be posted on signs along areas of the shore that have been treated. However, if you do not have a sign posted or the sign indicates that only algaecides were applied, there are no swimming restrictions.
When can I water my lawn following a treatment?
If you draw water from the lake for irrigation, be sure to read the sign posted along your shoreline at the time of treatment. Most irrigation restrictions do not apply to established lawns. However, it you water flowers or a garden, adhere to the irrigation restrictions posted on the sign.
Who oversees the plant control program?
Plant control activities are coordinated under the direction of the board’s environmental consultant, Progressive AE. Beginning in May and continuing through August, biologists from Progressive AE conduct GPS-guided surveys of the entire lake to identify problem areas, and detailed plant control maps are provided to our plant control contractors. Progressive then conducts follow-up surveys to evaluate contractor performance, and provides status reports to the board. Herbicide treatments are conducted by PLM Lake & Land Management Corp.
In Michigan, a permit must be acquired from the Department of Environmental Quality before herbicides are applied to inland lakes. The permit lists the herbicides that are approved for use, respective dose rates, use restrictions, and indicates specific areas of the lake where treatments are allowed. In addition to a state permit, federal regulations require herbicide applicators to acquire a pesticide general permit and to prepare and submit a pesticide discharge management plan.
The Spring Lake plant control program focuses primarily on invasive, exotic species. An exotic species is one that is found outside of its natural range. Exotic plant species that are potentially a threat to Spring Lake include Eurasian milfoil, curly-leaf pondweed, and starry stonewort. Early detection and rapid response is key to effective control of invasive aquatic plant species. The Spring Lake plant control program includes multiple plant surveys to detect invasive and nuisance plants and targeted herbicide treatments to control nuisance plant growth.
Nuisance aquatic plant control is the primary focus of the Spring Lake improvement program. In managing aquatic plants, it is important to remember that most plants are beneficial to the lake. Plants in lakes produce oxygen during photosynthesis, help stabilize shoreline and bottom sediments, and provide cover and habitat for fish and other aquatic inhabitants.
The objective of a sound aquatic plant control program is to remove plants only from problem areas where nuisance growth is occurring. Excessive removal of aquatic plants can have negative consequences. For example, broad-spectrum herbicide treatments can result in algae blooms and reduced water clarity which, in turn, can be detrimental to the fishery. Maintaining a diversity of beneficial plants is as important as controlling nuisance and exotic species.